Plantar ulcers, i.e., ulcers located on the bottom of the foot, are a source of concern for many diabetic patients. The ulcers are often caused by continuous elevated pressure that may be the result of, e.g., abnormal gait pattern, foot deformity, a foreign object, etc. The problem is made more acute by the loss of protective sensation and may be exacerbated by reduced blood flow found in the extremities of some diabetic patients.
Attempts to address the problem of plantar ulcers focus on off-loading the affected areas such that the pressure on the ulcerated area is reduced or eliminated during ambulatory activity. One of the most effective approaches involves the use of a total contact cast that mechanically unloads the affected area by providing a rigid cast extending from below the knee and including the patient's foot. The goal in forming a total contact cast is to shape the cast such that the ulcerated area experiences reduced pressure during ambulation by the patient.
Total contact casts do, however, suffer from a number of disadvantages. Among the disadvantages are the cost of total contact casting. The course of treatment for a plantar ulcer often extends for a period of about ten weeks. The ulcer must be monitored for healing, infection, etc. at least once per week. That monitoring requires removal of the cast and refashioning of a new total contact cast at each visit. In addition to cost, other disadvantages include inconvenience for the patient, as the length of each office visit is increased by the time required to fashion a new cast. Furthermore, the skill level of the cast technicians needed to fashion a total contact cast is high, limiting the availability of total contact casts to those patients with access to highly skilled medical personnel.
Other approaches to treating plantar ulcers involve the use of pre-made walkers. Some of these devices may include customizable insoles and/or air bladders to improve fit. The devices tend, however, to be bulky and uncomfortable to wear. In addition, because the devices are easily removed and replaced by the wearer, patient compliance with treatment plans is difficult to control and/or monitor. These problems are exacerbated by the bulkiness and discomfort of the devices. Further, clinical evidence of the efficacy of such devices in the treatment of plantar ulcers is obscure.